Commercial ovens may provide for closed system operation in which the oven volume is substantially sealed to retain heat and moisture and provide energy savings. Such closed system operation is particularly desirable for “combination ovens” that provide the ability to cook food using steam and fan driven (forced convection) hot air but may also be used in convection ovens (without steam) and rotisserie ovens.
In closed-system ovens, excess pressure within the cooking cavity caused by expanding steam and air may be vented through a condenser where the steam is cooled before exiting to the outside air, reducing heating of the kitchen environment. In common condenser designs, the steam is passed through a water bath which cools and condenses the steam. The temperature of the water bath is monitored and fresh, cool water is introduced into the water bath as the temperature rises. Excess water from the bath passes through an overflow into the building drain system.
Some foods, when cooked, produce significant quantities of grease which may be allowed to drain away from the food to be captured in a drip pan positioned at the bottom of the oven. The drip pan may be attached to a drain line to allow gravity draining of the grease into a removable collection container. One method of providing such a drainage system is described in U.S. Pat. No. 7,421,942 entitled: “Grease Collection System for Oven”, assigned to the assignee of the present invention, and hereby incorporated by reference.
Gravity drainage systems for grease can be an obstacle to efficient stacking of ovens if the lowermost oven is not sufficiently elevated to permit positioning of the drain containers beneath the oven. The drainage path for excess grease is normally separate from the exit path of steam through the condenser so that the overflow water from the condenser does not discharge grease into the drains where it may congeal.